The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Mobile Ad Hoc Networks (MANETs) are communication networks in which all nodes are mobile and communicate with each other via wireless connections. There is no fixed infrastructure with interconnected network infrastructure elements that maintain and exchange routing information. All nodes in a mobile ad hoc network are equal and there are no designated routers: all nodes can route data packets for each other, and data packets are forwarded from node to node in a multi-hop fashion. Due to the mobility of the nodes in a mobile ad hoc network, the topology of the network changes frequently and routes which were initially efficient may quickly become inefficient or even infeasible.
One technique used for routing data packets in mobile ad hoc networks is based on the Ant Colony Optimization (ACO) algorithm, which belongs to a larger field of algorithms referred to as Swarm Intelligence algorithms. A traditional ACO routing technique models the establishing of routes in a network after the mechanisms used by ant colonies to establish and maintain paths to desirable food sources. Ants randomly choose a path to a food source. On the chosen path, the ants deposit a chemical substance called “pheromone”, which allows other ants to follow the pheromone scent and hence the chosen path. When more ants traverse a path the pheromone deposit on that path gets more intense, thereby allowing more ants to become attracted to and use that path to travel to the food source and back. The concentration of the pheromone scent on paths to food sources evaporates after certain amount of time. Thus, longer and less traveled paths lose their pheromone scent faster than shorter and more traveled paths. For this reason, more ants would choose the shorter paths to food sources.
The traditional ACO routing technique does not use conventional routing tables that are exchanged between fixed network infrastructure elements. Instead, according to the traditional ACO routing technique a network node selects a route for forwarding a data packet based on a pheromone value associated with that route, where the pheromone value reflects the number of packets that traverse the route. However, the instability of nodes in a mobile ad hoc network limits the applicability of the traditional ACO routing technique because a pheromone value may not be suitable for establishing efficient and stable routes between the nodes in the network.